includes/Exception.php

   1 <?php
   2
   3 /**
   4  * MediaWiki exception
   5  * @addtogroup Exception
   6  */
   7 class MWException extends Exception
   8 {
   9         function useOutputPage() {
  10                 return !empty( $GLOBALS['wgFullyInitialised'] ) &&
  11                         !empty( $GLOBALS['wgArticle'] ) && !empty( $GLOBALS['wgTitle'] );
  12         }
  13
  14         function useMessageCache() {
  15                 global $wgLang;
  16                 return is_object( $wgLang );
  17         }
  18
  19         function runHooks( $name, $args = array() ) {
  20                 global $wgExceptionHooks;
  21                 if( !isset( $wgExceptionHooks ) || !is_array( $wgExceptionHooks ) )
  22                         return; // Just silently ignore
  23                 if( !array_key_exists( $name, $wgExceptionHooks ) || !is_array( $wgExceptionHooks[ $name ] ) )
  24                         return;
  25                 $hooks = $wgExceptionHooks[ $name ];
  26                 $callargs = array_merge( array( $this ), $args );
  27
  28                 foreach( $hooks as $hook ) {
  29                         if( is_string( $hook ) || ( is_array( $hook ) && count( $hook ) >= 2 && is_string( $hook[0] ) ) ) {     //'function' or array( 'class', hook' )
  30                                 $result = call_user_func_array( $hook, $callargs );
  31                         } else {
  32                                 $result = null;
  33                         }
  34                         if( is_string( $result ) )
  35                                 return $result;
  36                 }
  37         }
  38
  39         /** Get a message from i18n */
  40         function msg( $key, $fallback /*[, params...] */ ) {
  41                 $args = array_slice( func_get_args(), 2 );
  42                 if ( $this->useMessageCache() ) {
  43                         return wfMsgReal( $key, $args );
  44                 } else {
  45                         return wfMsgReplaceArgs( $fallback, $args );
  46                 }
  47         }
  48
  49         /* If wgShowExceptionDetails, return a HTML message with a backtrace to the error. */
  50         function getHTML() {
  51                 global $wgShowExceptionDetails;
  52                 if( $wgShowExceptionDetails ) {
  53                         return '<p>' . htmlspecialchars( $this->getMessage() ) .
  54                                 '</p><p>Backtrace:</p><p>' . nl2br( htmlspecialchars( $this->getTraceAsString() ) ) .
  55                                 "</p>\n";
  56                 } else {
  57                         return "<p>Set <b><tt>\$wgShowExceptionDetails = true;</tt></b> " .
  58                                 "at the bottom of LocalSettings.php to show detailed " .
  59                                 "debugging information.</p>";
  60                 }
  61         }
  62
  63         /* If wgShowExceptionDetails, return a text message with a backtrace to the error */
  64         function getText() {
  65                 global $wgShowExceptionDetails;
  66                 if( $wgShowExceptionDetails ) {
  67                         return $this->getMessage() .
  68                                 "\nBacktrace:\n" . $this->getTraceAsString() . "\n";
  69                 } else {
  70                         return "<p>Set <tt>\$wgShowExceptionDetails = true;</tt> " .
  71                                 "in LocalSettings.php to show detailed debugging information.</p>";
  72                 }
  73         }
  74
  75         /* Return titles of this error page */
  76         function getPageTitle() {
  77                 if ( $this->useMessageCache() ) {
  78                         return wfMsg( 'internalerror' );
  79                 } else {
  80                         global $wgSitename;
  81                         return "$wgSitename error";
  82                 }
  83         }
  84
  85         /** Return the requested URL and point to file and line number from which the
  86          * exception occured
  87          */
  88         function getLogMessage() {
  89                 global $wgRequest;
  90                 $file = $this->getFile();
  91                 $line = $this->getLine();
  92                 $message = $this->getMessage();
  93                 return $wgRequest->getRequestURL() . " Exception from line $line of $file: $message";
  94         }
  95
  96         /** Output the exception report using HTML */
  97         function reportHTML() {
  98                 global $wgOut;
  99                 if ( $this->useOutputPage() ) {
 100                         $wgOut->setPageTitle( $this->getPageTitle() );
 101                         $wgOut->setRobotpolicy( "noindex,nofollow" );
 102                         $wgOut->setArticleRelated( false );
 103                         $wgOut->enableClientCache( false );
 104                         $wgOut->redirect( '' );
 105                         $wgOut->clearHTML();
 106                         if( $hookResult = $this->runHooks( get_class( $this ) ) ) {
 107                                 $wgOut->addHTML( $hookResult );
 108                         } else {
 109                                 $wgOut->addHTML( $this->getHTML() );
 110                         }
 111                         $wgOut->output();
 112                 } else {
 113                         if( $hookResult = $this->runHooks( get_class( $this ) . "Raw" ) ) {
 114                                 die( $hookResult );
 115                         }
 116                         echo $this->htmlHeader();
 117                         echo $this->getHTML();
 118                         echo $this->htmlFooter();
 119                 }
 120         }
 121
 122         /* Output a report about the exception and takes care of formatting.
 123          * It will be either HTML or plain text based on $wgCommandLineMode.
 124          */
 125         function report() {
 126                 global $wgCommandLineMode;
 127                 if ( $wgCommandLineMode ) {
 128                         fwrite( STDERR, $this->getText() );
 129                 } else {
 130                         $log = $this->getLogMessage();
 131                         if ( $log ) {
 132                                 wfDebugLog( 'exception', $log );
 133                         }
 134                         $this->reportHTML();
 135                 }
 136         }
 137
 138         function htmlHeader() {
 139                 global $wgLogo, $wgSitename, $wgOutputEncoding;
 140
 141                 if ( !headers_sent() ) {
 142                         header( 'HTTP/1.0 500 Internal Server Error' );
 143                         header( 'Content-type: text/html; charset='.$wgOutputEncoding );
 144                         /* Don't cache error pages!  They cause no end of trouble... */
 145                         header( 'Cache-control: none' );
 146                         header( 'Pragma: nocache' );
 147                 }
 148                 $title = $this->getPageTitle();
 149                 echo "<html>
 150                 <head>
 151                 <title>$title</title>
 152                 </head>
 153                 <body>
 154                 <h1><img src='$wgLogo' style='float:left;margin-right:1em' alt=''>$title</h1>
 155                 ";
 156         }
 157
 158         function htmlFooter() {
 159                 echo "</body></html>";
 160         }
 161 }
 162
 163 /**
 164  * Exception class which takes an HTML error message, and does not
 165  * produce a backtrace. Replacement for OutputPage::fatalError().
 166  * @addtogroup Exception
 167  */
 168 class FatalError extends MWException {
 169         function getHTML() {
 170                 return $this->getMessage();
 171         }
 172
 173         function getText() {
 174                 return $this->getMessage();
 175         }
 176 }
 177
 178 /**
 179  * @addtogroup Exception
 180  */
 181 class ErrorPageError extends MWException {
 182         public $title, $msg;
 183
 184         /**
 185          * Note: these arguments are keys into wfMsg(), not text!
 186          */
 187         function __construct( $title, $msg ) {
 188                 $this->title = $title;
 189                 $this->msg = $msg;
 190                 parent::__construct( wfMsg( $msg ) );
 191         }
 192
 193         function report() {
 194                 global $wgOut;
 195                 $wgOut->showErrorPage( $this->title, $this->msg );
 196                 $wgOut->output();
 197         }
 198 }
 199
 200 /**
 201  * Install an exception handler for MediaWiki exception types.
 202  */
 203 function wfInstallExceptionHandler() {
 204         set_exception_handler( 'wfExceptionHandler' );
 205 }
 206
 207 /**
 208  * Report an exception to the user
 209  */
 210 function wfReportException( Exception $e ) {
 211          if ( $e instanceof MWException ) {
 212                  try {
 213                          $e->report();
 214                  } catch ( Exception $e2 ) {
 215                          // Exception occurred from within exception handler
 216                          // Show a simpler error message for the original exception,
 217                          // don't try to invoke report()
 218                          $message = "MediaWiki internal error.\n\n" .
 219                          "Original exception: " . $e->__toString() .
 220                          "\n\nException caught inside exception handler: " .
 221                          $e2->__toString() . "\n";
 222
 223                          if ( !empty( $GLOBALS['wgCommandLineMode'] ) ) {
 224                                  fwrite( STDERR, $message );
 225                          } else {
 226                                  echo nl2br( htmlspecialchars( $message ) ). "\n";
 227                          }
 228                  }
 229          } else {
 230                  echo $e->__toString();
 231          }
 232 }
 233
 234 /**
 235  * Exception handler which simulates the appropriate catch() handling:
 236  *
 237  *   try {
 238  *       ...
 239  *   } catch ( MWException $e ) {
 240  *       $e->report();
 241  *   } catch ( Exception $e ) {
 242  *       echo $e->__toString();
 243  *   }
 244  */
 245 function wfExceptionHandler( $e ) {
 246         global $wgFullyInitialised;
 247         wfReportException( $e );
 248
 249         // Final cleanup, similar to wfErrorExit()
 250         if ( $wgFullyInitialised ) {
 251                 try {
 252                         wfLogProfilingData(); // uses $wgRequest, hence the $wgFullyInitialised condition
 253                 } catch ( Exception $e ) {}
 254         }
 255
 256         // Exit value should be nonzero for the benefit of shell jobs
 257         exit( 1 );
 258 }
 259
 260